The effect of molecular conformation on electron-transfer rate will be studied in several systems. Prior work in our laboratories has shown that a large conformational effect is observed for hydrazine oxidation and reduction, resulting in the generation of non-equilibrium conformations upon reduction of hydrazine radical cations. It is proposed that this phenomenon will be general, and several examples will be studied to see if this is true. It is suggested that because radical anions of activated olefins undergo rapid cis to trans isomerizaton, this reaction can be used to generate unstable transcycloolefins of unusual reactivity. Biacridans will be studied to attempt generation of the unstable, twisted ground state expected from work on bianthrones. Olefins with both a strong electron-withdrawing and releasing group such as vinylogous amides will be studied mechanistically, to elucidate the pathways for electron transfer (is the electron transfer adiabatic or vertical?). A new mechanism is proposed and will be tested for the formation of anemonin from protoanemonin. The effects of through-space interaction in non-planar pi systems will be investigated. Understanding of redox mechanisms is important in understanding how enzymatic electron-transfer processes are controlled in biological systems. This proposal consists of model studies of the importance of molecular conformation in the control of rates of electron transfer.